1. Field of the Invention
The present invention pertains to adjustable support or bracing apparatus. In particular, it pertains to adjustable support or bracing apparatus suitable for temporarily supporting door frames in proper alignment while masonry work is performed adjacent thereto.
2. Description of the Prior Art
In the construction of buildings, it is often necessary to support a wall or form prior to the attachment of other structural members which are to eventually hold the walls or forms in place. Traditionally, this has been done by temporarily nailing wooden supports to the walls or forms which are removed when they are no longer needed. However, such procedures are wasteful of both materials and time. For this reason, recent construction techniques have been developed utilizing adjustable supports or braces to take the place of wooden structural members. These adjustable supports or braces can be used over and over, reducing cost in both labor and materials. Examples of such may be seen in U.S. Pat. Nos. 3,030,061; 3,171,627; and 3,574,981.
Similarly, in the installation of door frames, specially those made of metal in commercial buildings, it is necessary to temporarily support the door frame prior to the erection of adjacent walls. This is particularly true in masonry construction where there is nothing to support the door frame until the adjoining masonry wall is formed thereabout. Consequently, it may be necessary to construct temporary support or braces of some sort to hold the door frame in place until the masonry work is completed. Adjustable and reusable supports have been developed in the past few years to accomplish this purpose. Examples are shown in U.S. Pat. Nos. 1,824,998; 2,914,813; 2,914,814; 3,027,686; and 4,048,771.
While the temporary door frame supports of the prior art are definitely better than supporting the door frame with lumber braces, they have not been completely satisfactory for various reasons. Many of them are bulky, cumbersome to use and susceptible to damage or the loss of parts. Others require attachment to the ground or floor which is not always easy to do. Furthermore, attachment to the door and some fixed support is not always easy to accomplish since the attachment devices are not universal in angle of attachment. In addition, most of these devices do not provide for fine adjustment so that the door frame may be easily and accurately aligned or plumbed. Others are not positively connected at both ends so as to reduce the hazards of falling on workers. Because of the deficiencies of the prior art, none of these devices have found widespread use.